Developing Swedish grid trawl fishing of Norway lobster

Last changed: 17 April 2023
Norway lobster in basket

In the early 2000s, Swedish scientists and the fishing industry introduced and adapted the Norwegian Nordmøre shrimp grid for Norway lobster trawl fishing – the Swedish grid. The aim was to minimise by-catches of demersal roundfish like cod, without losing Norway lobster. 

In 2004 the grid became mandatory in Swedish waters, which made it possible to continue trawling Norway lobster despite weak cod stocks.

Norway lobster trawl fishing is also characterised by a high discard ratio of undersized lobster. To meet the upcoming landing obligation and limitation of quotas for by-catch species, fishers wanted to develop the grid further. Swedish fishermen Bertil Andersson (VG-350 Althea) and Ingvar Olsson (SD-669 Palermo) contacted the Swedish Secretariat for Selective Fishing to present new ideas. In 2015, development was completed and the trawl was evaluated scientifically. It was found to be highly effective in further reducing by-catches in grid trawl fishery.

Development - from traditional trawling to the Althea grid


Effective reduction of by-catches

Scientific comparison of catches between the Swedish grid trawl and the Althea grid trawl, targeting Norway lobster. All other species and undersized Norway lobster is counted as unwanted by-catch.


Swedish grid

Althea grid


Norway lobster   
(target size)

20,2 17,8 -12 %

Norway lobster
(under sized)

8,3 3,3 - 60 %


5,3 1,2 - 77 %
Cod 5,2 1,3 - 75 %
Plaice 21,7 8,3 - 62 %
Dab 60,1 8,1 - 86 %
Long rough dab     17,8 2,5 - 86 %



Hans C. Nilsson, Researcher
Department of Aquatic Resources, Institute of Marine Research, SLU , +46 10 478 40 40

Daniel Valentinsson, Researcher
Department of Aquatic Resources, Institute of Marine Research, SLU, +46 10 478 40 49